Aggression in group-housed laboratory mice: why can't we solve the problem?

Area of Science:

• Animal Welfare Science
• Laboratory Animal Husbandry
• Ethology

Background:

• Aggression is a major welfare issue in group-housed laboratory mice, leading to injury and compromising research validity.
• Current strategies to mitigate aggression primarily focus on social dominance and territoriality, overlooking other husbandry factors.
• Existing laboratory mouse housing conditions are unnatural, restricting species-typical behaviors and often involving aversive stimuli.

Purpose of the Study:

• To challenge conventional thinking regarding aggression in laboratory mice.
• To propose alternative perspectives on understanding and mitigating aggression.
• To investigate the influence of environmental control on aggressive behavior in laboratory mice.

Main Methods:

• This article presents a conceptual review and proposes new research directions.
• It critically examines current laboratory mouse housing and husbandry practices.
• It highlights the under-explored role of environmental control in animal welfare science.

Main Results:

• The study identifies a gap in current research, which has largely ignored the impact of environmental control on aggression.
• It suggests that unnatural housing conditions and lack of control contribute to stress and aggression.
• Alternative housing and husbandry approaches are needed to improve mouse welfare and research outcomes.

Conclusions:

• Giving laboratory mice more control over their environment is a crucial, yet understudied, avenue for reducing aggression.
• Re-evaluating housing and husbandry practices is essential for enhancing animal welfare and scientific rigor.
• Further research into environmental control can lead to improved management of aggression in laboratory mice.